Two-piece pipe end cap

ABSTRACT

A two-piece end cap for an industrial pipe is provided. The end cap comprises a planar end wall and a flexible side wall extending about the periphery of the end wall, the side wall having a lip extending inwardly from the bottom thereof, the lip having a groove therein within which the periphery of the planar end wall is seated, an oblique surface being present along the top of the lip extending downwardly from the side wall toward the end wall and terminating adjacent a lateral edge of the lip, and the side wall having at least one annular ridge extending about the inner periphery of the side wall for engagement with an exterior surface of a pipe upon insertion of the pipe into the end cap, the annular ridge being in a plane which is parallel to the planar end wall.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority pursuant to 35 U.S.C. 119(e) of U.S. application No. 61/202,242, filed Feb. 9, 2009, the entirety of which is herein incorporated by reference.

BACKGROUND OF THE PRESENT INVENTION

The present invention is directed to a two-piece pipe end cap.

Pipe end caps for large industrial pipes have been employed for over 40 years. More recently, two-piece pipe end caps have been provided. The advantage of using a two-piece pipe end cap was at the time related to ease of manufacture. That is, an extruded side wall could be wrapped around an extruded circular end wall to form the pipe cap. However, present two-piece pipe end caps employ an L-shaped end for the side wall upon which the end cap is placed and must somehow be secured (such as by tape).

However, such end caps frequently are difficult to place on the end of the pipe, become easily dislodged during handling, transit and storage, and/or difficult to remove. They also do not provide the maximum degree of pipe protection, as the material from which the end cap and side wall are produced is the same in each instance.

OBJECTS AND SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide a two-piece end cap for a pipe that may be easily assembled and which may be tailored to a specific end use due to the use of impact resistant materials.

In accordance with the present invention, there is provided a two-piece end cap for a pipe, comprising an end wall and a side wall extending around the periphery of the end wall, the side wall having a lip extending inwardly from the bottom thereof, the lip having a groove therein within which the periphery of the end wall is seated, an oblique surface being present along the top of the lip extending downwardly from the side wall toward the end wall and terminating adjacent a lateral edge of the lip, and the side wall having at least one annular ridge extending inwardly from the side wall to the interior of the end cap for engagement with an outer surface of a pipe upon insertion of the pipe into the end cap, with the at least one annular ridge extending about the inner periphery of the side wall in a plane parallel to the end wall.

In a preferred embodiment, the side wall has an alternating wave-trough configuration, and which may include embedded air channels within the within the wave portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in perspective of the end cap of the present invention when inserted onto the end of a pipe.

FIG. 2 is a view in perspective of the end cap of the present invention when viewed from the bottom.

FIG. 3 is a cross-sectional view of the end cap of the present invention as shown in FIG. 1.

FIG. 4 is a cross-sectional view of the end cap of the present invention as shown in FIG. 2.

FIG. 5 is a cross-sectional view of a portion of the end cap of the present invention as shown in FIG. 3.

FIG. 6 is a cross-sectional view of another embodiment of the present invention showing a different wall configuration.

FIG. 7 is a cross-sectional view of another embodiment of the present invention showing yet another wall configuration.

FIG. 8 is a view in perspective of the extruded sheet forming the side wall of FIG. 5.

FIG. 9 is a view in perspective of the extruded sheet forming the side wall of FIG. 6.

FIG. 10 is a view in perspective of the extruded sheet forming the side wall of FIG. 7.

DETAIL DESCRIPTION OF THE PRESENT INVENTION

The present invention will be described in relation to FIGS. 1-10.

The two-piece end cap 1 of the present invention is intended as an end cap for a pipe 7 as shown in FIG. 1. The end cap 1 comprises a planar end wall 3 and an extruded side wall 5 extending around the periphery of the end wall 3.

The extruded side wall 5 has a lip 27 extending inwardly from the bottom of the extruded side wall. The lip 27 has a lateral groove 13 therein within which the planar end wall 3 is seated. An oblique surface 11 is provided along the top of the groove 13 extending downwardly from the side wall 5 toward the end wall 3 and terminating at a lateral edge of the lip 27.

The oblique surface 11 serves several purposes. Primarily, the oblique surface assists the placement of the planar end wall 3 into groove 13 upon insertion of the end wall 3 between the peripheral side wall 5. Further, such oblique surface serves as a stop for the end of the pipe upon insertion into the end cap as shown in FIG. 5.

The extruded side wall 5 has at least one annular ridge 9 extending from the inner surface of the side wall 5 to the interior of the end cap for engagement with the surface of a pipe upon insertion of the pipe into the end cap. Multiple annular ridges 9 are shown in FIGS. 2, 4, 5, 6 and 7, which ridges extend circumferentially about the inner periphery of the side wall and are substantially parallel to the plane of the end wall 3 and perpendicular in orientation to the longitudinal axis of the end cap. Such ridges serve to enhance the grip of the end cap to the end of the pipe upon being inserted into the end cap.

The uppermost extent of the side wall 5 is preferably tapered outwardly to provide a tapered end 15 (FIG. 5) to permit ease of insertion of the pipe into the end cap.

FIGS. 6 and 7 depict additional embodiments of the extruded side wall 5.

In FIG. 6, the extruded side wall includes embedded air spaces 21 formed by the extrusion of continuous channels within the side wall. As shown, the air spaces alternate from one side to the other of the side wall in an offset manner, and are located within the bottom portion of the wave along the entire extent of the side wall. As also shown in FIG. 6, annular ridges 17, 19 are shown to be present in an offset manner on the outer and inner surfaces, respectively, of the wall 5 in the form of alternating waves and troughs.

In FIG. 7, the side wall 5 is extruded to form a wavy or sinusoidal configuration having alternating waves and troughs, such that annular ridges 25, 23 are formed both on the outer and inner surfaces, respectively, of the wall 5.

The embodiments of FIGS. 6 and 7 particularly enable the end cap to provide good fit performance for a wide variety of pipe tolerances and under a wide variety of weather conditions (as plastic pipe caps typically expand or contract in an amount 5 to 10 times that of steel).

FIGS. 8-10 depict the side wall of the end cap of FIGS. 5-7 in the form of various cross-sectional configurations of an extruded cut sheet prior to being wrapped end-to-end to form the continuous side wall of FIG. 2. Advantageously, the extruded sheet can be cut to whatever dimension is required to fit the pipe upon which the end cap is to be placed. The cross-sectional configuration of the sheet can also be easily modified due to the fact that the sheet is extruded along the direction of the circumference of the resulting side wall which is formed.

The end cap of the present invention is easily formed by the steps of providing a length of extruded side wall of the length corresponding to the circumference of the side wall of the end cap (as shown in FIGS. 8-10), forming the length of extruded side wall into a continuous side wall by joining the ends of the length of extruded side wall by suitable means, and then either placing the planar end wall downwardly into engagement with the bottom of the continuous side wall so that the periphery of the planar end wall becomes inserted into lip 27 at the bottom of the circular side wall, or wrapping the side wall around the end wall and joining the ends. The planar end wall does not need to be permanently attached to the side wall as it is seated within the annular lip 27 and held therein. The respective ends of the cut extruded side wall member may be joined together by adhesive bonding, spot welding, mechanical connectors, etc. to form a joint 29 (FIG. 2). The manner of joining is not critical to practice of the present invention.

One advantage of the present invention is that the material used to form the end wall 3 may be tailored to enhance the physical properties of the end cap. For instance, it may be advantageous for the end cap to be comprised of an impact resistant material, which material is more impact resistant than the material which comprises the side wall. The end cap may also be of a different thickness than the material used to form the extruded side wall—e.g., the end cap may be greater in thickness than the side wall for purposes of enhanced durability.

Another advantage of the present invention is the ability to form an endless number of pipe caps for different sizes of pipes by the cutting and connecting the cut extruded wall together to form a side wall ring of the desired size without having to provide such side wall rings by injection molding which would require providing different tooling for each desired size ring. The end wall disc may be easily formed by die cutting to provide a disc size configured to fit within the desired side wall ring size. Such flexibility in manufacturing is very valuable in the marketplace.

Another advantage of the present invention is that the end cap may be shipped in two pieces in “knocked-down” form. The end caps may be stacked flat and the side wall rings can be coiled to reduce shipping space. The end caps may be easily assembled into the side wall rings in the field by the end user by being inserted within the groove at the bottom of the wall.

By way of an alternative embodiment, the end wall may be spot welded to the bottom of the side wall ring to provide a more permanent attachment of the end wall to the side wall ring. In such a case, the groove at the bottom of the side wall may or may not be used to provide additional securing means for the end wall to the side wall ring. However, the annular lip at the bottom of the side wall ring would still be present. In such a case, the end wall may be spot welded at either the junction between the end wall and the bottom of the side wall ring, or at the junction of the end wall and the side wall ring at the interior of the end cap.

The planar end cap may be made by die cutting sheets of material, preferably extruded sheets. The side wall may be made by any conventional extrusion process. The material employed will typically be polyethylene for the reason that it is cost-effective, flexible, and provides good weather resistance. Either low density or linear low density polyethylene are preferred materials for use in the present invention. One of ordinary skill in the art can readily determine suitable materials for use in the present invention. 

1. A two-piece end cap for a pipe, comprising a planar end wall and a flexible side wall extending about the periphery of the end wall, the side wall having a lip extending inwardly from the bottom thereof, the lip having a groove therein within which the periphery of the planar end wall is seated, an oblique surface being present along the top of said lip extending downwardly from said side wall toward said end wall and terminating adjacent a lateral edge of the lip, and the side wall having at least one annular ridge extending about the inner periphery of the side wall for engagement with an exterior surface of a pipe upon insertion of the pipe into the end cap, said annular ridge being in a plane which is parallel to the planar end wall.
 2. The two-piece end cap of claim 1, wherein said side wall is formed from an extruded sheet having opposing ends joined together.
 3. The two-piece end cap of claim 1, wherein said side wall includes multiple annular ridges.
 4. The two-piece end cap of claim 1, wherein said at least one annular ridge includes an air channel.
 5. The two-piece end cap of claim 1, wherein said at least one annular ridge comprises a series of annular ridges each having an alternating ridge-trough configuration.
 6. The two-piece end cap of claim 1, wherein said ridge includes an air channel extending along the extent thereof. 